Method of contacting liquids



DE@ MD, R935.. E. T. PUMMILI.

n METHODV OF CONTACTING LIQUIDS Original Filed Aug. 25, 1932 liv NSQ QwS FR Patented Dec. 10, 1935 UNETED STATES PATENT OFFIQE Socony-VacuumOil Company, Incorporated,

New York, N. Y., a corporation of New York Original application August25, 1932, Serial No.

Divided and this application August 19, 1935, Serial N0. 36,924

1 Claim.

This application is a division of my copending application Serial No.630,391, filed August 25, 1932.

This invention has to do with methods of control fo-r treating systemswherein one liquid is contacted with another. Specifically, it has to dowith the control of the movement of reagent from one vessel to anotherin a continuous series or such vessels and with the proportioning ofreagent originally fed to the system.

The invention is applicable to any system treatmg a liquid with anotherliquid of different speciiic gravity, and where the use of specificliquid is mentioned in this specication it is not intended that thespecification shall be limited by such recitation.

The present form of the invention is designed for use in the treatmentof petroleum products, broadly hereafter referred to as oil, withsulphuric acid, and the discussion will for convenience be confined tosuch system.

In the treatment of oil with acid there has been developed a system madeup of several units, in

each of which the oil to be treated is contacted with a mixture of acidand acid sludge in such a manner that the sludge-acid mixture isemployed in a Volume much in excess of the volume of oil to be treated.From each of these units g ,Y a settled oil is withdrawn to be passed toa furcountercurrent to the oil sequence; and to each unit strongersludge-acid mixture is supplied from the unit prior in series.

Such a system is set forth in United States Patent 1,652,399 to S. J.Dickey, in United States Patent 1,625,195 to S. J Dickey, and in UnitedStates Patent 1,792,003 to S. J. Dickey.

Other systems less elaborate comprise merely a series of tanks orseparating vessels through which the oil to be treated passes in onedirection while the reagent passes through the series in the oppositedirection being pumped by manually controlled pumps from one vessel toanother. It will be noted that in both the older system and the systemshown by Dickey, in his several patents previously referred to, thereare a plurality of points for manual control and this presents inherentdifficulties in keeping the operation in balance resulting in costlyattention. Not only does lack of balance in such systems result in aloss of smooth working, but it frequently results in damage to thetreated product.

It is an object of this invention to provide a method of operationwherein the original proportioning and the proportional transfer ofreagent in such a system is subject to a simple accurate and flexiblecontrol.

For the purposes of the present specification, the system of controlpresented by this invention is represented as operating upon a treatingsystem similar to that of Dickey, in his several patents previouslyreferred to. It is equally applicable without great modification to anyother similar system or in fact to any system wherein one liquid iscountercurrently treated with another. The drawing showing an oiltreating system with the attached control method of this invention isattached ,to and made a part of this specification. In the drawing,vessels i, 2, and 3 are separating vessels. Oil to be treated entersfrom outside the system under gravity head or pump pressure and passesthrough fitting 5, an enlarged detail of which is shown. This ttingconsists of a body 5 into which line 4 leads, ending in a jet. Enteringthe body 5 is a line 6 connected to the body of the separating vessel I.Due to the jet action of the entering oil a quantity 25 of the separatedreagent or sludge-acid mixture in the bottom of separating vessel I isWithdrawn and mixed with the oil and the mixture passes on through lineI to enter separating vessel I about midway if its height. By a propercontrol or adjustment of the sizes of jets and orices, it is possible tocontact with the oil a relatively great volume of sludge-acid mixture.The oil and sludge-acid are allowed to separate by settling in theseparator vessel I and the oil passes through line I0 to a, similartreatment in separator vessel 2 and from thence by line Il to a similartreatment in separator vessel 3. Fittings 5' and 5 are the same asfitting 5; line 6 and 6" exercise the same function as line 6; lines 8and 9 exercise the same function as line 1. Treated oil leaves thesystem (which may be composed of any suitable number of separatorvessels though here shown as only three) through line l2 and passes tostorage. A portion of it is withdrawn through line I3 for actuating thetransfer of reagent as hereinafter explained and as set forth in Dickey,in his several patents previously referred to. Fresh reagent enters thesystem from an outside source through line I4 and passes into 50 fittingI'I. Treated oil from line I3 is placed under pressure by pump I5 anddistributed through line I6. Entry of reagent into the sys tem isactuated by a jet of this treated oil entering tting I'I through valveI8 and there 55 entraining reagent from line I4 which it discharges intoline 9. Due to the constant addition of reagent to the separating vessellast in the series, the level of reagent or sludge-acid would build upin this vessel if its withdrawal were not controlled. To control thiswithdrawal I have provided a liquid level control device I9 acting uponthe effective interface between the two liquids in separating vessel 3.There is no actual interface in separating vessel 3, the mixture merelybecoming more and more concentrated as regards sludge-acid toward. thebottom and more and more concentrated as regardsoil toward the top, butby equipping float chamber I9 with connections, one of which leads tothe region where there is the most concentrated sludge-acid and theother to the region where there is the cleanest oil I am enabled toestablish an actual interface in the iioat chamber which occupies thesame position as the effective interface in the separating vessel. Inthis oat chamber I provide a float, floating upon the interface and bythis float I actuate valve I8. Liquid level controls of this type arewell known and many forms of linkage between the valve and float areused. `They may for instance be an actual linkage of levers, or the oatmay actuate a valve admitting compressed air to a diaphragm whichoperates the main valve, or electrical connections and motors may beused. All these methods are well developed, all are widely used, and anymay be used herein. They form no portion ofy this invention, and forsimplicity of drawingare designated merely by dotted lines connectingeach oat and the valve it operates. Similar liquid level float controlsare provided for separator vessels I and 2 at I9 and I9" acting uponvalves I8' and I8". A valved line 20 is provided forV withdrawing spentsludge-acid from separator vessel I, the vamount-ofl spent sludge-acidso withdrawn is adjusted in proportion to the amount of untreated oilentering through line 4. This adjustment may be made automatic by meansof commercial instruments for controlling ratios. When sludge iswithdrawn from separator vessel I, a decrease in level actuates floatcontrol I9 which in turn opens valve I8, causing the transfer ofsludge-acid from separator vessel 2 to separator vessel I. In a similarmanner separator vessel 2 will adjust its content of sludge-acid bywithdrawing sludgeacid from separator vessel3. Separator vessel 3 willin turn replenish its supply by drawing fresh acid from line I4. In thismanner adjustment of the valve in line 20 regulates the proportion ofacid to oil throughout theentire system, doing away with the ineffectivemanual control heretoiore found necessary. It is also possible for thissystem to be operated in a slightly d iflerentman-v ner. The amount ofacid drawn from line I4 may be regulated in proportion to the amount ofoil passed through line 4,'in which case the liquid level controller oneach separator vessel would operate to control the withdrawal of thesludgeacid from the vessel to which it is connected 5 rather than thereverse as in the above explanation. It is apparent that the method ofoperation herein disclosed is capable of controlling accurately andsimply the proportions and conditions of Contact of one liquid withanother in any system l0 of countercurrent treatment wherein twononmiscible liquids of differing specific gravities are made use of.While the method has been designed primarily for the treatment of oiland the example and explanation given are pertinent to 15 that art, themethod is capable of working with any system of non-miscible liquids ofdifferent specific gravities. Accordingly, I claim this methcd in itsbroadest equivalents except as limited by the following claim. 20

I claim:

The process of treating liquid with a liquid reagent largelynon-miscible therewith and differing in specicgravity therefrom,comprising establishing a plurality of pools of liquid formed into upperand lower layers consisting principally of the liquid being treated andthe reagent respectively passing the liquid to be treated from a sourceof supply to one of the pools withdrawing reagent from said one pool andcommingling the same with the liquid to be treated during its passage tothe said pool; permitting the separation in the pool of the reagent andthe thus treated liquid, withdrawing and passing liquid from said upperlayer to and through successive pools of the said plurality of poolswhile commingling the same with reagent withdrawn from each pool priorto its introduction into that pool and permitting separation of theliquid and reagent in the respective pools, introducing fresh 0 y liquidreagent into the last of the pools in the series, maintaining aneffective interface between kthe layers in each pool at a predeterminedlevel,

effecting the passage of reagent from the lower layer in each of thepools to the next preceding 5 pool upon the lowering of the effectiveinterface in the preceding pool, and withdrawing used reagent from saidone pool in such quantity as to assure a desired processing of theliquid with the resultant advancement of the reagent from pool to poolas the interface between the layers in each pool is lowered to therebyeffect a control over the rate of feed of the reagent to the last poolof the series,'and its maintenance in the process during which it'isrecirculated from and 55 to each of the pools and commingling withliquid under treatment'as it is passed thereto.

EVERT T. PUBJMILL.

